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State-of-the-art techniques for 3D reconstruction are largely based on volumetric scene representations, which require sampling multiple points to compute the color arriving along a ray. Using these representations for more general inverse…

Computer Vision and Pattern Recognition · Computer Science 2024-10-01 Benjamin Attal , Dor Verbin , Ben Mildenhall , Peter Hedman , Jonathan T. Barron , Matthew O'Toole , Pratul P. Srinivasan

We present an updated model of the cosmic ionizing background from the UV to the X-rays. Relative to our previous model (Faucher-Giguere et al. 2009), the new model provides a better match to a large number of up-to-date empirical…

Cosmology and Nongalactic Astrophysics · Physics 2020-02-05 C. -A. Faucher-Giguere

With this paper we participate to the call for ideas issued by the European Space Agency to define the Science Program and plan for space missions from 2035 to 2050. In particular we present five science cases where major advancements can…

Instrumentation and Methods for Astrophysics · Physics 2021-01-26 A. Zanella , C. Zanoni , F. Arrigoni-Battaia , A. Rubin , A. Pala , C. Peroux , R. Augustin , C. Circosta , E. Emsellem , E. George , D. Milakovic , R. van der Burg , T. Kupfer

Reversible data hiding (RDH) has been extensively studied in the field of information security. In our previous work [1], an explicit implementation approaching the rate-distortion bound of RDH has been proposed. However, there are two…

Information Theory · Computer Science 2023-07-18 Na Wang , Chuan Qin , Sian-Jheng Lin

We introduce a model that can accurately simulate radiation from undulator sources for ray tracing applications. It incorporates several key effects relevant to 4$^\text{th}$ generation synchrotron sources, such as electron emittance,…

Accelerator Physics · Physics 2024-10-18 Manuel Sanchez del Rio , Juan Reyes-Herrera

Hyperspectral cameras provide numerous advantages in terms of the utility of the data captured. They capture hundreds of data points per sample (pixel) instead of only the few of RGB or multispectral camera systems. Aerial systems sense…

Image and Video Processing · Electrical Eng. & Systems 2026-01-09 Thomas P. Watson , Eddie L. Jacobs

We present a novel numerical implementation of radiative transfer in the cosmological smoothed particle hydrodynamics (SPH) simulation code {\small GADGET}. It is based on a fast, robust and photon-conserving integration scheme where the…

Astrophysics · Physics 2009-06-23 M. Petkova , V. Springel

We consider the inverse problem of the broken ray transform (sometimes also referred to as the V-line transform). Explicit image reconstruction formulas are derived and tested numerically. The obtained formulas are generalizations of the…

Mathematical Physics · Physics 2011-01-07 Lucia Florescu , Vadim A. Markel , John C. Schotland

We have developed non-sequential ray-tracing software which is aimed to be widely used, along with air- shower simulations, in the design of optical systems for cosmic-ray experiments. The code is based on the ROOT geometry library to…

Instrumentation and Methods for Astrophysics · Physics 2015-05-30 Akira Okumura , Masaaki Hayashida , Hideaki Katagiri , Takayuki Saito , Vladimir Vassiliev

Reversible data hiding (RDH) is one special type of information hiding, by which the host sequence as well as the embedded data can be both restored from the marked sequence without loss. Beside media annotation and integrity…

Computer Vision and Pattern Recognition · Computer Science 2018-11-08 Dongdong Hou , Weiming Zhang , Jiayang Liu , Siyan Zhou , Dongdong Chen , Nenghai Yu

An efficient and accurate image reconstruction algorithm for ultrasound tomography (UST) is described and demonstrated, which can recover accurate sound speed distribution from acoustic time series measurements made in soft tissue. The…

Numerical Analysis · Mathematics 2021-11-17 Ashkan Javaherian , Ben Cox

Traditional ultrasound simulation methods solve wave equations numerically, achieving high accuracy but at substantial computational cost. Faster alternatives based on convolution with precomputed impulse responses remain relatively slow,…

Medical Physics · Physics 2025-10-14 Felix Duelmer , Mohammad Farid Azampour , Nassir Navab

Gaussian Splatting is a powerful tool for reconstructing diffuse scenes, but it struggles to simultaneously model specular reflections and the appearance of objects behind semi-transparent surfaces. These specular reflections and…

Graphics · Computer Science 2026-04-02 Kunnong Zeng , Chensheng Peng , Yichen Xie , Masayoshi Tomizuka , Cem Yuksel

In this paper a new efficient algorithm for computation of radio wave ray trajectories is described. The algorithm is based on an original second-order difference scheme with a specific "length-conservation" property, which allows to…

Instrumentation and Methods for Astrophysics · Physics 2010-10-19 Leonid Benkevitch , Igor Sokolov , Divya Oberoi , Thomas Zurbuchen

Existing concealed object segmentation (COS) methods frequently utilize reversible strategies to address uncertain regions. However, these approaches are typically restricted to the mask domain, leaving the potential of the RGB domain…

Computer Vision and Pattern Recognition · Computer Science 2025-02-24 Chunming He , Rihan Zhang , Fengyang Xiao , Chengyu Fang , Longxiang Tang , Yulun Zhang , Linghe Kong , Deng-Ping Fan , Kai Li , Sina Farsiu

High redshift sources suffer from magnification or demagnification due to weak gravitational lensing by large scale structure. One consequence of this is that the distance-redshift relation, in wide use for cosmological tests, suffers…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 Madhura Killedar , Paul D. Lasky , Geraint F. Lewis , Chris J. Fluke

Ultrasound Tomography has seen a revival of interest in the past decade, especially for breast imaging, due to improvements in both ultrasound and computing hardware. In particular, three-dimensional ultrasound tomography, a fully…

Computational Physics · Physics 2020-05-27 Ashkan Javaherian , Felix Lucka , Ben Cox

Exploratory analysis of scalar fields on surface meshes presents significant challenges in identifying and visualizing important regions, particularly on the surface's backside. Previous visualization methods achieved only a limited…

Graphics · Computer Science 2024-05-30 Kai Lawonn , Monique Meuschke , Tobias Günther

In two-dimensional spectrographs, the optical distortions in the spatial and dispersion directions produce variations in the sub-pixel sampling of the background spectrum. Using knowledge of the camera distortions and the curvature of the…

Astrophysics · Physics 2009-12-08 Daniel D. Kelson

The optical constants of ruthenium in the spectral range 8 nm to 23.75 nm with their corresponding uncertainties are derived from the reflectance of a sputtered ruthenium thin film in the Extreme Ultraviolet (EUV) spectral range measured…